Objective:

Variability in soil organic matter (SOM) qualities and characteristics influences the proportion of permafrost carbon that can be processed into greenhouse gases. This research project will quantify methane production potentials in a thermokarst-lake landscape and examine if SOM compounds and characteristics can be used as predictors of anaerobic carbon cycling potentials.

Approach:

The first phase of research examines samples from a 5.9-m long lake core and 40-m deep permafrost tunnel at Vault Lake, Fox, Alaska. Samples will be analyzed for their soil organic matter (SOM) properties and composition and incubated to measure anaerobic methane production potentials. SOM characteristics will be correlated with methane production potentials to determine which factors serve as predictors of methane production. The second phase of research will examine paleo-thermokarst lake profiles in a yedoma exposure near Cherskii, Russia. SOM characteristics will be analyzed and used to estimate methane emissions from a paleo-thermokarst lake environment using the determined correlations.

Expected Results:

Soil organic matter (SOM) characteristics and composition can be used as an accurate predictor of methane production potentials in thermokarstlake environments. SOM quantity and quality will vary with depth and location along the profiles and the differences will be reflected in the methane production potentials. It is expected methane production potentials will be highest in samples with high concentrations of labile SOM. Estimating methane emissions from SOM composition data will allow for better estimates about the potential effects of thawing permafrost in Earth’s changing climate in both paleo-thermokarst lake profiles and thermokarst lakes in the present and future.

Potential to Further Environmental/Human Health Protection

Climate change represents a major threat to human health and community well-being through increased weather extremes, changes in storm and hydrologic patterns and changes in the range and ecology of diseases. The addition of greenhouse gases to the atmosphere, including the potent greenhouse gas methane, contributes to climate change. Improving and refining the understanding of methane production from natural environments, in addition to anthropogenic emissions, will help model the future climate scenarios.

Supplemental Keywords:

methane, permafrost, soil organic matter

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.